[solatic]

> have never measured it

That's because it's practically impossible to collect objective data here, i.e. without confounding factors.

A product where the user spends 99+% of their time reading/consuming is almost certainly easier to use with a GUI. The market settled on thumb-flicking for doom scrolling instead of a button or scroll wheel interface, for a reason.

A product where the user spends 99+% of their time writing is almost certainly easier to use with a keyboard. Most sane people do not write essays on their phones with two thumbs; a keyboard and a proper word processor are preferred.

Most products fall somewhere in the middle. Most products have multiple interfaces, some primarily for consuming information and some primarily for producing it, and thus would find different inputs more productive in different modes. When people claim that they find one input type is more productive than the other, most likely is that their particular use-patterns fall more in-line with the one most aligned with their use-patterns.